Luciferases are enzymes that catalyze reactions that emit light. Luciferases are named according to their source organisms such as beetles (firefly) (see for example U.S. Pat. No. 5,641,641) or marine organisms. Examples of bioluminescent marine animals include: Renilla, also known as sea pansies, which belong to a class of coelenterates known as the anthozoans. In addition to Renilla, other representative bioluminescent genera of the class Anthozoa include Cavarnularia, Ptilosarcus, Stylatula, Acanthoptilum, and Parazoanthus. All of these organisms are bioluminescent and emit light as a result of the action of an enzyme (luciferase) on a substrate (luciferin) under appropriate biological conditions. Prior studies have demonstrated that all of the above-mentioned anthozoans contain similar luciferases and luciferins. See, for example, Cormier et al., J. Cell. Physiol. 81: 291-298 (1973). The luciferases and luciferins from each of these anthozoans will cross-react with one another to produce the characteristic blue luminescence observed in Renilla extracts. Each of these luciferases has similar biochemical properties, and the biochemical requirements for bioluminescence were reported to be identical (U.S. Pat. No. 5,292,658) regardless of the anthozoan from which the luciferase was derived.
Different luciferases have different properties with regard to substrate specificity and intensity of light emission and stability of the bioluminescent signal, which is commonly measured by a luminometer. Luciferases are useful as transcriptional reporter genes and in imaging reporter gene expression in living subjects and many other applications in molecular biology.
Luciferases that utilize coelenterazine luciferin as a substrate generate a flash of bioluminescence of a magnitude that can be useful for certain molecular biology reactions such as high through-put screening. This use among others would benefit from the extension of the time period of the bioluminescent signal.